Grinding disk



June 26, 1934. l, R, SHUE 1,964,539

GRINDING DISK Filed Aug. l0, 1931 26 WWW/w Patented Julie 26,"1934UNITED STATES PATENT OFFICE 1,964,539 GRINDING msx Ingle R. Shue,Beloit, Wis., assigner to Gardner Machine Company, Beloit, Wis., acorporation of Illinois Application August 10, 1931, Serial No. 556,050

15 Claims. (Cl. 51-2'09) wheels, and more particularly to wheels of thedisk type.

Y Wheels of this type are usually used in a ma;- chine operating atrelatively high speeds which create centrifugal forces of considerablemagnitude. The wheels must therefore have sufficient strength towithstand such forces. 'I'he abrading material is made in diierentgrades for different classes of work, and the strength of the abradingmaterial varies with the different grades. 5 It is preferable that somemeans be provided for strengthening disks of any grade but especiallyfor disks of a soit grade.

The general object of the invention is to provide a new and improvedgrinding disk which may be made in` any desired grade of hardness, andwhich vhas great strength not solely dependent upon the grade ofabrading material used.

More specically, the object is to provide a grinding disk of thischaracter -comprising two layers of molded material, one being anabrading material 0i` `any desired grade, while the other is a materialof great strength intimately conneeted to the layer of abradingmaterial.

Another object is to provide a grinding disk of this character, in therear or strengthening layer of which are embeddedreinforcing andsecuring means for attaching the disk to a supporting wheel. Y

A further object is-to provide a narrow-faced annular form or" diskcomprising two layers 'of the above-mentioned character, wherein therear or strengthening layer not only underlies the layer of abradingmaterial but also extends inwardly beyond said abrading layer withreinforcing and securing means embedded inA said inwardly extendingportion.

Other objects and advantages will become apparent from the followingdescription taken in connection with the accompanying drawing, in which:

Figure l is a perspective View, partially broker. away, or' a assemblyembed-r tion.

Fig. 2 is a. perspective view similar to Fig. 1 but ora modified form ofdisk.

Fig. 3 is an enlarged fragmentary sectional View of both rorms of f 1n agrinding disk embodying the features of the invention, two layers ofmolded materialning the features of the inventizgnately attached to eachother are provided. One layer, comprising the portion available for usein grinding, is made of abrading material of any desired grade suited tothe work to be done. The other layer is made of molded material hav- 00ing relatively great strength and forming the rear part of the disk.

As shown in the drawing, a supporting wheel is provided which is adaptedto be secured to a driving means, as by screws (not shown) passingthrough holes 11 and adapted to be threaded into a flange on the drivingspindle of a grinding machine (not shown). Positioned with its rear faceagainst the supporting wheel 10 is a grinding disk, indicated generallyat 12.

' The preferred embodiment of the grinding disk 12, shown in Fig. 1,comprises a layer 13 constituting the front portion of the disk and madeof molded abrading material, usually comprising abrasive grains and abond of any desired grade suitable for the class of work the disk isexpected to do. Since such material often lacks suihcient strength, itis desirable to provide some strengthening means in order that the diskmay withstand the large centrifugal forces aris- 80 ing when the disk isrotated at relatively high speeds.

To strengthen the layer 13 and thus prevent cracking thereof due to saidforces, a second layer 14 of molded material is formed at the rear of.the layer 13 and is intimately connected therewith to preventseparation thereof. The rear layer 14 is made of any suitable moldedmaterial having great tensile strength. Such material may be bondingmaterial alone or with a suitable proportion of granular, fibrous orother suitable material mixed therein. Preferably a metallicreinforcement is molded in the rear layer 14 but if none is usedvthislayer should be composed of material having inherently greater 95tensile strength than the iront abrasive layer 13 so as to withstand thecentrifugal forces set up in the disk when rotated at high speed.

To give added strength to the disk, reinforcing means is preferablyused. As illustrated herein 100 the reinforcing means comprises a Wiremesh 15, although expanded metal or other ioraminous `material may beused in its stead. The wire mesh 15 is preferably embedded in the rearface of the rear layer 14 and is coextensive with said 105 layer.

The means for securing the grinding disk 12 to the supporting wheel 10comprises pairs of cooperating members, one embedded in the disk 9nd.'the other removable therefrom. As illusno trated herein, the embeddedmembers comprise a plurality of nuts 16 positioned in a predeterminedarrangement relative to the face areaof thedisk comprising a pluralityof circular,

radially spaced rows, and embedded in the rear layer 14. Threaded intocach nut 16 is a screw 17 constituting the removable member andextending through the supporting wheel 10 with its head preferablycountersunk in the rear face of the supporting wheel. The nuts 16 bearagainst the inner face of the wire mesh and clamp the mesh securelyagainst the supporting wheel so that the rear layer 14 receives all ofthe centrifugal and torsional stresses set up in the disk as a whole.The mesh preferably is at least coextensive with the areas bounded bythe circles of the inner and outer rows `of nuts. The form of securingmeans illustrated herein is merely exemplary, and it is contemplatedthat other forms may be used.

Since the disk can be used for grinding purposes only down to the nuts16, the line of division between the layers 13 and 14 may lie iiush withthe inner face of the nuts 16 as is clearly shown in Fig. 3. Thus, thelayer 13 occupies that portion of the disk which is available forgrinding purposes while the layer 14, which gives strength to the disk,occupies that portion ofzthe disk which is not available for grindingpurposes.

In many disks, only the portion adjacent the periphery is used. For thisclass of work, the grinding disk may be in the form of an annulus 20, asshown in Fig. 1. However, the internal stress in the disk due tocentrifugal forces remains relatively large. To give the disk suiiicientstrength to withstand such forces, the inner or rear layer, formed ofmaterial having greater strength than the annulus 20A which is made ofabrading material, not only underlies the entire area of the annulus butalsoextends radially inwardly therefrom, as shown at 21. Thus, thev rearlayer is of maximum size for a given diameter of disk. l

This form of disk may also include a plurality of nuts, similar to thoseshown in Fig. 2, for securing the grinding disk to the supporting wheel10, and a reinforcing means such as a wire mesh to give additionalstrength to the disk. The

-nuts and wire mesh are embedded in the rear layer, some of the nutsbeing positioned in the inwardly extending portion 21 of the rear layerin order that the stresses set up will be distributed over the whole,area of the rear layer.

From the above description, it will be apparent that I have provided agrinding disk in which the front or abrading portion may be made in` anydesired grade of hardness, and which is strengthened by a rear layer ofmolded material having great tensile strength to resist the stresses dueto centrifugal force. 'I'he rear layer has embedded therein the meansfor securing the disk to a supporting wheel and preferably also has`reinforcing means to give additional strength to the disk. The rearlayer, where both layers are in the form of annuli, may also extendinwardly beyond the front layer of abrading material with certain of thesecuring members .embedded in the inwardly extending portion.-

I claim as my inventionr- 1. A grinding disk comprising, in combination,a layer of moulded abrading material constituting the front portion ofthe disk, a second layer intimately attached to the rear face of saidfirst layer and made of a-r'elatively stronger moulded material,reinforcing means embedded in said' second layer and coextensivetherewith, and securing means embedded in said second layer.

2. A grinding disk comprising, in combination, a layer of mouldedabrading material constituting the front portion of the disk, a secondlayerl intimately attached to the rear face of said rst layer and madeof a relatively stronger moulded material, and reinforcing and securingmeans embedded in said second layer, said second layer having athickness equal to that of said means.

3. A grinding disk comprising, in combination, a layer of mouldedabrading material, a second layer of relatively stronger mouldedmaterial, and reinforcing and securing means embedded in said secondlayer, said second layer comprising that part of the disk renderedunavailable for grinding purposes by said means.

4. A grinding disk comprising, in combination, a layer of mouldedabrading material, a second layer of relatively stronger mouldedmaterial, reinforcing means embedded in the outer face of said secondlayer, and a plurality of securing means embedded in said second layeragainst said reinforcing means, the inner faces of said securing meanslying flush with the inner face of said second layer.

5. A grinding disk comprising, in combination, a front layer of mouldedabrading material, a rear layer of relatively stronger moulded material,a wire mesh embedded in the rear face of the rear layer, and a pluralityof nuts embedded in said rear layer and bearing against the front faceof said mesh, the front faces of said nuts lying flush with the frontface of said rear layer.

6. A grinding disk conprising a plurality of 110 layers of differentcompositions, and means moulded in the rearmost layer for reinforcingthe latter and for securing the disk as a whole to a supporting wheel.

7. A grinding disk adapted to be secured to a supporting wheelcomprising, in combination, two concentric annular layers, the firstlayer constituting the rear portion ofthe disk and having reinforcingand securing means molded therein and constructed for securing the diskas a whole to said supporting wheel, and the second layer constitutingthe front portion of the disk and having a larger internal diameter thansaid rst layer.

V8. A grinding disk adapted to be secured to a supporting wheelcomprising, in combination, two concentric annular layers, the rst layerconstituting the rear portion of the disk and having reinforcing meansand securing means molded therein for securing the grinding disk as awhole to said supporting wheel, the reinforcing means being coextensivewith said first layer, and the second layer constituting the frontportion of the disk and having a larger internal diameter than saidfirst layer. f

9. 'A grinding disk adapted to Abe secured to a supporting wheelcomprising, in combination, two concentric annular layers, the rst layerconstituting the rear portion of the disk and having reinforcing andsecuring means embedded therein, said first layer having a thiclmessequal to the thickness of the reinforcing and securing means, and thesecond layer constituting the front portionof the disk and having alarger internal diameter than said first` layer.

10. A grinding disk adapted to be secured to a supporting wheelcomprising, in combination, two concentric annular layers, the firstlayer constituting the front portion of said disk, and the second layerbeing made of molded material and 150 1,964,589 constituting the rearportion of the disk andv having a smaller internal diameter than. saidrst layer, said second layer having a plurality of securing meansembedded therein for attaching the disk to the supporting wheel withcertain of said securing means located in the part of said second layerwhich extends inwardly beyond said rst layer.

11. A grinding disk adapted to be secured to a supporting wheelcomprising, in combination, two concentric annular layers, the firstlayer constituting the front portion of said disk, and the sec# ondlayer constituting the rear portion of the disk and having a smallerinternal diameter than said first layer, said second layer having a wiremesh embedded therein and a plurality of nuts for clamping said disk tothe supporting Wheel bearing against the Wire mesh with certain of saidnuts located in the part of said second layer which extends inwardlybeyond said rst layer.

12. A grinding disk adapted to be secured to a supporting wheelcomprising, in combination,

two concentric annular layers, the rst layer constituting the frontportion of said disk, and the second layer constituting the rear portionof the disk and having a smaller internal diameter than forcing sheet ofwire mesh positioned adjacent the rear face of said disk, a plurality ofnuts scattered about the front face of said mesh and bearing againstsaid mesh, a rear layer of bonded granular material in which said nutsand mesh are embedded with the front face of said rear layer ilush withthe front face of said nuts whereby said rear layer constitutes thatportion of the thickness of the disk which said nuts and mesh occupy,and a front layer of bonded abrasive material intimately connected tothe rear layer, and

a plurality of screws, one for each nut,vextending through thesupporting wheel and threaded into said nuts.

14. A grinding disk comprising, in combination, a layer of moldedabrading material constituting the front portion of `the disk, a secondlayer made of molded material and intimately attached to the rear faceof said first layer, reinforcing means molded in said second layer, andsecuring means molded in said second layer for securing the grindingdisk as a whole to a supporting wheel.

15. A grinding disk comprising, in combination, a layer of moldedabrading material constituting the front portion of the disk, a secondlayer made of molded material and intimately attached to the rear faceof said rst layer, a plurality of circular, radially spaced rows ofsecuring members molded in said second layer for securing the grindingdisk as a whole to a supporting wheel, I

and reinforcing means molded in said second layer and being 'at leastcoextensive with the area bounded by the circles of the inner and outerrows of securing members. no

INGLE R. SHUE.

